Safety device.



G. P. KNAPP.

SAFETY DEVICE. APPLICATION FILED JULY 25, 1912.

1,060,608. Patented May 6, 1913.

WITNESSES. l/VI/E/VTOR M 7 m f fi/ GEORGE P KNAIPP, 0F BRIDGEPORT, CONNECTICUT.

sAFE'rr DEVICE.

Specilicationci amen; Patent.

Patented May 6, 1913.

Application filed July 25, W12. Serial No. 711,58.

the-frame of the press and so actuated by the treadle that before the working head of the press can be connected with, and operated by, the driving power the. guard will be moved into its protecting position surrounding the work field, the connecting mechanism between the tripping treadle ofthe machine and the several operative parts being such as to preclude the possibility of the press being tripped before the hands of the operator are entirely removed from the working field of the machine and the guard in its protecting position.

It further consists in the particular mechanism whereb the treadle of the machine is connected to t e several parts so that as soon as the working head is operably-connected with the power driven pulley and begins, its movement, the guard is released from its protectin position and is moved out of the work fiel to leave the press clear for the introduction of work for the next operation,

thereby saving much valuable time and increasing the output ofthe machine.

In the accompanyi'n drawings :Figure 1, is a side elevation o a power press provided with my improved safety device, and, Fig. 2, is a plan view of the swinging guard detachedfrom the machine.

This invention is illustrated in connection with a bench power press in which 1 is an upright frame mounted on a base or table 2, supported on legs 3 and havin bearings forme in-its upper part for a orizontal shaft 4 to. the forward end of which is connected a vertically sliding tool carrying head G-ada'pted to cause the operating tool to act on work held in a die block mounted on the table 2. On the rear end of the shaft 4 is mounted a loose driving pulley 7 arranged to derive motion and power through a belt (not shown) and on the shaft 4, bet-ween the drive pulley 7 and the frame 1 of the machine, 1s mounted a trip clutch 8 which may be of any one of the many forms commonly used in similar places, having a sliding pull bar 9 a downward movement of which will throw the clutch into operation and cause the drive pulley to be actively connected with the shaft 4 for one revolution. A. return spring 10 attached at one end to the frame 1 and at the other end to the bar 9, and properly tensioned, will tend to retainthe bar 9 in its raised position or will return it to such position after it has been pulled'down to oper! ate the clutch. These several parts being well known to users of power presses, a'more detailed description is omitted.

Upon 'the side of the frame 1 in guideways attached to or integral with said frame is mounted a vertically sliding bar 11 preferably formed of a straight'vertical part to pass freely through the guide way with an ofi'set portion at its up or end to connect with the slidin clutch ar 9 as shown so that when the ar 11 is pulled down the clutch will beoperated'to connect the drive pulley and the shaft of the press. Also upon the side of the press frame 1 and slightly to the rear of the sliding bar 11 is pivoted a latch 12 preferably made as. shown with an upwardand forward projecting arm 13,

made to terminate in a pointed latch-tooth toeng'age a notch in the rear side of the slid-- ing bar 11, the notch so located that when engaged by the latch the bar will be locked in its uppermost position, and prevented from operatin the clutch until released. An upward an backward projectin arm 14 on the'latch is provided with an a just-able contactscrew 15 the dpurgose of which will be presently describe guard 16 preferably made as shown inFig. 2, wit-h a cross arm 17 and two parallel arms 1819, is pivoted to a bracket 20 made integral with or attached to the-frame l of the machine in such manner-that the forward cross arm may be moved up and down in front of the working field of the presses illustrated in dotted lines in the drawings. This guard 16 is padded at its forward end and adapted so to inclose the work field of the press when in its lower position as to, prevent the introduction of the hands of the operatoror othe obstruction, and when in its raised position,

to leave thework field clear, and a spring is provided, attached at one end to the frame 1 and at the other end to the guard, and is its-rear end that it will overlie the latch arm 14 and its setscrew 15 so that a downward movement of the guard will cause the latch 12 to be operated to free the slidebar 11 and permit it to operate the clutch bar 9', and the set screw 15 will permit of such an-ad ustment that this unlocking of the clutch oper'- ating parts will not take place until the guard has reached a position 1n',1ts downward movement to preclude the introductlon of the hands of the operator into the working field of the press or if the hands are in the working field'the guard W1ll be prevented from moving down far enough to effect the unlocking of the clutch trip. V

For the positive and timely actuation of the several parts described there is provided a floating lever 22 attached at one endby 1 means of adraw rod 23 with the slide bar 11 25 v the guard 16 at a point forward of 1ts p1vand by means of a similar draw rod 24 with otal 'connectionwith the frame of the. ma-

chine, and a draw rod 25 is connected at one end to the floating lever 22 and at its other end with an operating lever 26 preferably in the form of a treadle pivoted at the rearend to the supporting legs of the press and extending to the front of the press in easy reach of the operators foot. 1

The operation of'm device will be readily understood to be as ollows: The material to be operated on.is introduced by hand into.

the holder or fixture in the die block 5 and the hands of the operator-withdrawn from the working field of the press and'the oper-' at-ing lever 26 pressed down. The floating lever 22 is drawn down and, by reason of the sliding bar 11 being locked in its upward position by the latch 12, the lever draws down the guard against the action of its spring till it entirely incloses the work field of the machine at which time the latch arm 14 is depressed and the latch 13 withdrawn from the notch in the sliding clutch bar 9 and the latter is then free and is drawn down to trip the clutch and permit the drivepulley 7 to act on the press head 6 and cause I it to perform its work on" the piece inthe die block 5 and while this is being done the return spring 21 will lift the guard 16- awayscribed above. Should the hands of the op-' erator or any obstruction be left in the working field when the treadle lever 26 is depressed it will interfere with the dolwnward movement of the guard 16 and the etch 12 will not bewithdrawn from the notch'in the trip bar 11 and-the press cannot be operated 'until the obstruction is removed. Particular attention .is called to the operation of the fioating'lever22 whereby the guard is permitted to rise and clear the work field as soon as the press has beentripped, whereas, until the guard has been lowered sufficiently to insure a clear fieldg'the press cannot be tripped. I.

WhatiI plaim as my ,infiention is 1. The combination with the driving clutch of a power pressand operatedby a treadle in common therewith, and a. guard pivoted to swing into'position to protect the operating field of the, press, of a floating lever' interposed between the actuating I treadle and the operated parts substantially as shown. V

The combination with a power press having a constantly moving drive pulley and a tripping clutch between said pulley and the working head of the press, of a swinging-guard adapted to be moved to surround the work field of the machine, and tripping I mechanism embodying a floating lever sub-,

stantially as shown and connected to first positively move the guard into protecting position and then trip the clutch, all substantially as shown.

3. In a power press the combination with a latched clutch tripping rod, of a fioatin .lever connected at one end with the'clutc trip and at the other end with the swingin guard and actuated through a third an intermediate connection with an operating lever, all substantially as shown and described.

4. The combination with alatched .tripping rod of a power press of av swinging guard adapted to move into and out of the working field of the press and actuated by a treadle in common with thepress triplpmlg atc rod, the guard adapted to release, thev ofthe tnppi'ngro when the guard in its movementhasreached a positlon to protect the working field of thepress, all substan tially as shown. Q i I 5. In a power press and in combination, a power driven, reci rocating, tool-carrying head provided wit a tripping clutch between the powersupply and the head and a latched actuating rod therefor, a swin guard arran ed to move into and out o the workingfiel of the press, a floating lever connected atone end to the latched actuating rod of the clutch and at the other end to the swinging guard andat its central pa'rt with an operatin lever, means to trip the latch on the clutc actuating rod when the guard lsbrought into position to guard the v working field'of the machine, a spring to Copieaoi' this patent may be obtained for normally hold the power clutch open and a spring to normally hold the guard in av osition to permit free access to the wor ing field of the press, all substantially as, and for the purpose, set forth.

6. In a power press a latched connecting rod for actuating the power clutch connected to one end of a floating lever, a pivoted guard frame adapted to swing into positionto guard the workingfield of-the press against the action of a spring and connected to the other end of the floating lever, an operating lever connected to the central part of the floating lever, the several parts and points of connection so arranged that the first movement of the operating lever will cause the guard to be moved into position to guard the working field of the press and free the power clutch whereupon the latter will be operated and the guard will be allowed to return to its normal position by reason of its spring, all substantially as shown.

7. In a power press 'a sliding head and a driven pulley having an intervening clutch operated by a sliding connection normally locked in open position, a swinging guard normally held Withdrawn from the work field of the press and adapted, when moved "into position to guard the work field of the press, 'to unlatch the sliding connection of the clutch, and a floating lever connected to act on both the swinging guard and the five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

